With reference to prior art FIG. 1, in some satellite antenna systems 100 a single antenna (feed horn) 120 is connected to a transceiver 101, where the transceiver combines the functionality of both a transmitter and a receiver. In these embodiments, typically, the transceiver has a transmit port and a receive port. The transmit and receive ports are connected to an antenna feed 105. Antenna feed 105 generally comprises an orthomode transducer (OMT) 130, a polarizer 110, and the feed horn 120.
The feed horn, in this satellite antenna system arrangement, is a component that can convey RF signals to/from a remote location (such as a satellite). Feed horn 120 is connected to polarizer 110 and communicates transmit and receive RF signals between the polarizer and the feed horn. Signals communicated between the feed horn and the polarizer are circularly polarized. In linearly polarized systems, a polarizer is not required and a feed horn connects directly to an OMT. The polarizer is configured to convert linearly polarized signals to circular polarized signals and vice versa. Although described as two signals, these signals are communicated through a single output port of the polarizer and the polarizer communicates the two signals to a common port of the OMT. Moreover, the transmit and receive signals remain isolated due to at least one, or any combination of, polarization, frequency, and time diversity.
In addition to the common port, the OMT further comprises a transmit port and a receive port that are attached to matching ports on the transceiver housing. Thus, the OMT serves as a waveguide configured to connect a common port with at least a transmit port and a receive port. The OMT acts as a combiner/splitter of an RF signal so that a receive signal and a transmit signal can be communicated through the same feed horn with orthogonal polarizations.
Although this satellite antenna system is successfully employed in many systems, a need exists for improved systems that address issues of size, robustness, installation accuracy, tolerance issues, and the like. This is explained in more detail below.
First, attaching the feed horn, polarizer, and OMT to the transceiver can result in a bulky, volume consuming antenna system. It is typically desirable to make electronic components smaller for cost and aesthetic reasons, as well as other reasons. Also, generally, the components of the system need to be oriented relatively precisely and a bulky assembly such as this can introduce difficult design constraints with respect to the orientation of the antenna feed in reference to the reflector.
Second, generally the transceiver and the antenna feed are located outdoors exposed to the elements. This exposure can lead to water ingress (leakage) into the antenna feed and resultant flow into the transceiver, where electrical components can become damaged. One approach for minimizing the leakage problem is to seal the antenna feed's exposed connections with an epoxy or silicone solution. However, with the numerous connection points and edges, water can infiltrate the antenna feed. Indeed, each separate component in the antenna feed introduces an additional connection point that provides an opportunity for moisture to enter into the transceiver electronics by way of the antenna feed.
Third, each separate antenna feed component contributes to the length of time it takes to install the satellite antenna system in the field. Furthermore, each separate antenna feed component contributes to a chance of incorrect installation such as by installing the polarizer backwards, or reversing the transmit and receive ports.
Fourth, it is not uncommon for each part of the antenna feed to be manufactured by different companies. Each antenna feed component must then be connected to the adjoining components, and with each connection comes an increased opportunity for tolerance errors, which can increase the opportunity for moisture to enter the antenna feed and for performance degradation.
Thus, a need exists for improved satellite antenna systems, methods and devices for addressing these and other issues.